"I have agreed to represent Ms. Lohan on the condition that she complies with all of the terms of her probation, including a requirement of jail time that was imposed by Judge Marsha Revel," Shapiro tells UsMagazine.com in a statement.

Lohan, 24, entered Shapiro's sober living home, Pickford Lofts, Thursday -- five days before she is required to turn herself over to the authorities.

Mom Dina Lohan and ex Samantha Ronson were photographed visiting the troubled star in the luxe Hollywood facility, where residents live in lofts with designer kitchens, Internet access and flat-screen TVs.

"Ms. Lohan is suffering from a disease that I am all too familiar with," Shapiro -- who started the center after his son, Brent, died of a drug overdose in 2005 -- tells Us. "Hopefully, I can be of assistance to Ms. Lohan and Judge Revel in implementing a treatment approach recommended by medical professionals for Ms. Lohan’s long term recovery and sobriety."

But according to Deputy Kathy Roberts, Lohan's new attorney is not officially recognized in the eyes of the court just yet.

"The court has received no notification of any change of counsel status on the part of Ms. Lohan," Roberts tells Us. "We haven't heard anything about any documents being filed. We haven’t received any documents. Whatever [Shapiro] is saying, it's unrelated to the courts at this time."

TMZ previously reported that Shapiro will try to convince Revel to reduce or eliminate Lohan's jail sentence, though Deputy District Attorney Danette Meyers tells RadarOnline.com it won't work: "It's a moot point to ask Judge Revel to send Ms. Lohan to rehab only as Judge Revel has already sentenced her."